The ecoclimatic assessment for the potential establishment of Earias vittella and Maruca vitrata in New Zealand : A dissertation submitted in partial fulfilment of the requirements for the Post Graduate Diploma in Applied Science

Abstract

The computer-based model CLIMEX (Sutherland & Maywald 1985) was used for the assessment of the establishment potential of the tropical pest species Earias vittella and Maruca vitrata in New Zealand. Biological parameters from literature concerning the artificial rearing of both pest species were used in conjunction with their current distribution to create ecoclimatic indices. The indices were used to assess the potential for establishment of both pest species in New Zealand. Future climate changes as a result of the "Greenhouse" phenomenon were also investigated using two scenarios. One allowing for a minimal climate change, and the other allowing for an extreme climate change. Current climatic conditions do not favour the establishment of either pest species. Similarly, a minimal change in climate of 1.5°C would not allow establishment. When the extreme climate change was used, five locations in the north of the North Island were found to have some ecoclimatic similarities with both pest species current distribution. However these changes are in the upper predicted temperatures for "Greenhouse" change, 55 years beyond the present day. Therefore, under current climatic conditions, Earias vittella and Maruca vitrata, according to the analysis using CLIMEX, do not have the potential to establish in New Zealand.